Method and device for treating an ingot or the like in the course of its solidification in an ingot mould or the like



USS NG AN DIFIC R THE INGOT 0R T LIKE IN ATION IN AN INGOT LIKE 5 Sheets-Sheet 1 April 24, 1962 J. DA v METHOD AND DEVICE FOR TREATI THE COURSE OF ITS s MOUL Filed June 1'7, 1958 5 Sheets-Sheet 2 THE LIKE IN IN AN INGOT ATING AN INGOT OR J. DAUSSAN TRE MOULD OR THE LIKE Ill g lll velhm an 3 8 A \L THE COURSE OF ITS SOLIDIFICATION METHOD AND DEVICE FOR 5 4% g ow w @v 0% April 24, 1962 Filed June 17, 1958 mm mm 2:

April 24, 1962 H J. DAUSSAN 3,030,679 METHOD AND .DEVICE FOR TREATING AN INGOT OR THE LIKE IN THE COURSE OF ITS SOLIDIFICATION IN AN INGOT MOULD OR THE LIKE Filed June 17-, 1958 5 Sheets-Sheet 3 412T r \Jl I Ell April 24, 1962 H. J. DAUSSAN 3,030,679 METHOD AND DEVICE FOR TREATING AN meow OR THE LIKE THE COURSE OF ITS so IN LIDIFICATION IN AN INGOT MOULD OR THE LIKE Filed June 1'7, 1958 5 Sheets-Sheet 4 I l I E I April 24, 1962 DAUSSAN I 3 030,679

H. J. METHOD AND DEVICE FOR TREATING AN INGOT OR THE LIKE IN THE COURSE OF ITS SOLIDIFICATION IN AN INGOT MOULD OR THE LIKE Filed June 17, 1958 5 Sheets-Sheet 5 Illll 9 United Stats ate p 3 030 679 METEOD AND DEVIfIE l GR TREATENG AN IN- GOT 9R THE LIKE IN THE COURSE OF ITS SOLIDIFICATION IN AN I THE L NGOT MOULD GR v The present invention relates to treating ingots of steel, ferrous alloys or other alloys in a mould, such as an ingot mould for the purpose of controlling the solidification of the head of the ingot.

Whatever method of casting is employed, and more particularly when it concerns ferrous metals cast in ingot moulds open at their upper end, advantage is to be gained 1n accelerating the solidification of the surface of the bath of molten metal at the end of filling the mould or even during the filling (notably when bottom casting) so as to avoid discharges and projections of steel resulting from rupture of the upper crust, notably in the case of efiervescent steels, and to reduce hollows and defects in the head and consequent large amount of waste, segregations and notably sulphides.

In the case of bottom casting killed steel, it is already known to spray the surface of the bath of molten metal at the end of pouring after a lapse of time (very limited by the solidification of the metal in the molten metal supply passageways) so as to initiate the shrinkage hollow which is fed with metal more or less eifectively by a short pouring of some seconds.

A spraying or the like has been attempted in the case of non-killed effervescent steels, but the danger of sudden contact of water and molten metal renders the operation practically impossible.

In both cases, and above all in the case of effervescent steels, spraying effected without precautions could indeed cause explosion of the ingot in the course of solidification when it would seem that danger no longer exists and fatal accidents have occurred. In any case, spraying with water could only result in the sudden solidification of the head of the freshly poured ingot without it being possible to choose the moment or to methodically control the region where the solidification should start or should be accelerated and with no other physico-chemical intervention than a pure and simple cooling.

The purpose of the invention is to permit not only cooling in a controlled manner the head of ingots at the chosen moment after pouring but also immediately after the pouring jet has stopped and even during the filling of the ingot mould in the case of bottom casting, with the possibility of localizing the cooling at a predetermined region of the surface of the molten metal bath without danger of projection and/or discharge of molten metal thereby avoiding formation in the head of the ingot of large hollows and segregations.

An object of the invention is to provide a method of treating an ingot in the course of its solidification in an ingot mould, which comprises cooling in a controlled manner the periphery of the surface of the poured metal by providing a cooling effect on the peripheral portion of said surface by evaporation, employing the heat of said metal, of a liquid which is supplied progressively and maintained on said peripheral portion without possibility of violent contact with the poured metal.

To this end there can be used:

(a) A liquid and in particular water in the free state.

(b) A liquid solution and in particular an aqueous solution of nsiO -mNa O the ratio Na O/SiO- being for example between 1/ 1.5 and 1/4.

(0) Water of constitution and/or crystallization which is liberated and then evaporated by the heat emanating from the poured metal by utilizing, for example, boric acid B'O H containing 43.7% Water of composition, borax (B O Na 10H O) which when heated loses its water of crystallization, or a mixture of these products in any proportion, or alternatively hydrated neutral carbonate of sodium CO Na lOI-I 'O which could also be utilized in the form of an aqueous solution.

The liquid, whether free or liberated by heat is disposed on or within a retaining support of such shape that it covers said peripheral portion of the ingot.

Another object of the" invention is to provide a device for use in carrying out the aforementioned method and comprising a support which, owing to the shape of its upper'face and/or to the nature of its wall, forms for the liquid to be evaporated a ring-shaped or frame-shaped vessel Whose contour corresponds to that of the peripheral portion of the ingot surface to be cooled.

Further features and advantages of the invention will be apparent from the ensuing description, with reference to the accompanying drawings, to which the invention is in no way restricted.

In the drawings:

FIG. 1 is a partial vertical longitudinal sectional view of an ingot mould provided with a device embodying the invention placed on an effervescent steel ingot in the course of solidification;

FIG. 2 is a corresponding plan view;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1;

FIG. '4 is a partial view similar to FIG. 3 on an enlarged scale;

FIG. 5 is a vertical sectional view of a modification of the device of the invention in position on a bottomcast killed steel ingot;

FIGS. 6 and 7 are views in vertical section and plan respectively of another modification of the device of the invention;

FIG. 8 is a vertical longitudinal sectional view of another device embodying the invention in position on an ingot;

FIG. 9 is a plan view of the device shown in FIG. 8;

FIG. 10 is a sectional view taken along line 10-10 in FIG. 8;

FIG. 11 is a vertical elevational partly sectional view on a scale larger than that of FIGS. 8 and 10 of a nest or multitude of passageways in the first stage of production;

FIG. 12 is a partial sectional view taken along the line 12-12 of FIG. 11 perpendicular to the passageways;

FIG. 13 is a sectional view similar to that of FIG. 11 of said series of passageways at another stage of production;

'FIG. 14 is a sectional view similar to FIG. 13 of the finished series of passageways forming the support in position on the ingot;

FIG. 15 is a view of the underside of a portion of one of the liquid supply pipes;

FIG. 16 is a sectional view taken along line 16-16 of FIG. 15; I

FIG. 17 is an elevational view, with parts cut away, of, on one hand, supports for two ingot moulds placed side by side and forming annular vessels placed at the upper part of the moulds on top of the poured metal, and, on the other hand, a water supply device supplying water-to said supports by way of spray heads;

FIG. 18 is a corresponding plan View:

FIG. 19 is a vertical sectional view on an enlarged scale of one of the supports forming a vessel;

FIG. 20-is a sectional view of a strip of a single wall corrugated board which is progressively onushed in the direction toward the end from which said band is rolled '2 a in the form of a spiral to form the support shown in FIG. 19;

FIG. 21 is a vertical sectional view of one of the spray heads on a scale larger than that of FIGS. 17 and 18; 'FIG. 22 is a partial horizontal sectional view taken along line 22-42 of FIG. 17 on an enlarged scale;

FIG. 23 is-a vertical sectional view of a modification of the spray head, and

FIG. 24 is a partial plan view of the base of the spray head and a sectional view of the auxiliary conical member disposed in the latter.

In the embodiment shown in FIGS. 1 to 4, the device A embodying the invention is adapted to control the cooling of the head of an ingot x of effervescent steel top cast in an ingot mould L having a rectangular horizontal cross-sectional shape the corners of which are rounded.

The device A consists of a rectangular support or frame which has a size in plan smaller than that of the inner cross-section of the mould L and is substantially homothetic to the inner cross-sectional shape of the mould. The frame has a substantially U-shaped crosssection. Its base 1 is fiat and its outer flange 2 and inner flange 3 are perpendicular to the base. The flange 2 is larger than the flange 3 which latter forms a central passage 4.

The support A which constitutes a ring-shaped (the terms ring-shaped, annular and the like are used in the broad sense and may include supports of square and rectangular and other such shapes in addition to generally circular shapes) or frame-shaped vessel, can be of any material (for example sheet steel, substantially .calendered cardboard, thick paper, wood, or plastic material) which is a good or bad heat conductor. This material can be porous or water-tight if it is a good heat conductor. *Its thickness must be such that it does not oppose the cooling effect due to evaporation of the liquid under the effect of the heat given off by the head of the ingot due to conductivity, if the wall of the device is composed of a liquid-tight material which is a good conductor (for example metal), to contact with this liquid which filters through the porous wall if the porous material (-for example cardboard) is not a heat conductor or is a bad heat conductor, or to conductivity and contact if the material is a good conductor and porous (for example powdered metal).

The thickness of the wall of the support A for example if sheet metal is used, could be about 1 mm. or even less present there are provided inside the U-shaped section vessel rein-forcing ribs or webs which impart thereto sufficient strength for handling and transport and possibly re-use of the device, since it could be abandoned on the head of the ingot or retrieved after the final example wood, charcoal, or pozzolana) comprising cells or small cavities which when impregnated with water or a liquid solution absorb and retain the latter while permitting evaporation. Alternatively, the annular trough or vessel could be previously filled with such a mass which could be rendered unitary therewith by any suitable means, for example by a network or fabric which covers it and is fixed, for example by clips or an adhesive, to the upper edge of the outer flange 2 over a part of,.or the whole of, the periphery of the latter.

The device is media the followin manner:

When the mould L has been filled with non-killed steel, that is, a molten steel giving off large amounts of gases in the course of its solidification, the peripheral solidification (denoted by the hatching) is allowed to reach the lines 8 (FIGS. 1 to 4) that is,until a face substantially 'homothetic to the inner face 9 of the mould L has been obtained, the cross-sectional shape of this face 9 being a rectangle abca (FIG. 2) in the plane of the top surface of the ingot. This solidification necessarily starts at the periphery of the molten metal bath due to contact with the inner face 9 of the cold wall of the mould L and spreads toward the axis XX of the ingot and mould, in a direction parallel with the inner face 9 of the mould unless scum, slag or an accumulation of impurities rising from the bottom of the mould starts a premature solidification at the center of the bath, which could be avoided by distributing over the surface of the bath a fiuidifying agent or suitable product or by drossing the bath in accordance with the known practice.

At this moment the support A is placed on the already solidified peripheral zone of the surface 10, water 7 having been previously poured in the support. Thereafter it is merely necessary to continue to supply water without danger, for example by a controlled jet or stream of water so that the solidification of the head of the ingot occurs under the best conditions, that is, by a progressive centripetal shrinkage of the cross-section of the unsolidified part 11.

The gases formed during solidification of the effervescent ferrous metal, of which the major part is CO and a smaller part notably CO hydrogen and nitrogen, are given off progressively toward the center of the head of the ingot in accordance with the shrinkage of the rectangle abcd, which is controlled by the regulated cooling resulting from evaporation of the water 7. This is obviously the most rational safe method of obtaining a sound ingot up to complete solidification of the ingot.

The shapes in the lengthwise direction of the not yet solidified part in the successive stages of solidification are shown in FIGS. 1 and 3 by dot-dash lines 12 and 13. In the course of the process, the metal rises somewhat in the central passage formed by the support and solidifies, for example in accordance with the contour 14 and in extremis the profile 14 shown in dot-dash line (FIG. 4) substantially without over-flowing which in any case would not present a grave inconvenience,

since the over-flowing metal is received in the annular vessel A where it solidifies.

It will be observed that it is always possible to cause the metal to descend in the central passageway 4 of the support A by means of any of the known materials having a calming action on the effervescent steel (for example aluminum).

This central passageway 4 could be used for supplying in extremis the ingot with active elements, such as bcrax, fluoride of calcium or sodium, hydrated sodium carbonate, slaked lime, excess silica, or hydrated sodium silicate.

Without the support A as is known by steel makersthe closure of the head of the ingot occurs in a haphazard manner very often prematurely with formation of a bridge across the rectangle abcd which gives rise to multiple craters and discharge of steel with the consequential known disadvantages of various types or explosions of the in ots well after closure of the ingot head.

, All these disadvantages are therefore avoided by using the device of the invention owing to the perfect progressivene-ss of the solidification in the direction from the periphery toward the axis of the ingot, if the latter has a cross-sectional shape substantially in the form of a square, regular polygon or a circle, or toward the plane of symmetry YY (FIG. 3) parallel with the large sides if the ingot has a substantially flat rectangular cross-sectional shape as shown.

The foregoing is obviously true, whatever the crosssectional shape of the ingot mould.

FIG. concerns the bottom casting of killed steel in an ingot mould having any horizontal cross-sectional shape, such as a square, rectangle or circle.

In the absence of the device of the invention, it is known, as mentioned hereinbefore, to spray the upper surface of the ingot so as to accelerate the solidification of its head.

The killed steel x solidifies very rapidly on the surface of the molten metal bath in the ingot mould L as soon as the jet of molten metal 18 in the bottom casting method is stopped and very often during the filling of the mould, and this is manifested by formation, on the surface of the bath, of a crust whose thickness varies with the composition of the metal but which is at least about one centimetre. After a pause of several minutes after pouring the metal into the mould to allow the crust to become sufficiently thick, the head of the ingot in the course of solidification is abundantly sprayed with water under pressure without particular attention and in a substantially oblique direction so as to accelerate formation of the shrinkage hollow within the ingot where the metal is still in the liquid state and is substantially viscous or even pasty, for example in the zone pqrs. This spraying, effect-- ed without regard to the amount, does not permit localizing in a certain manner the formation of the shrinkage hollow on the axis of the ingot, which in consequence cannot be filled as it should be by successively starting and stopping once or a plurality of times the jet of molten metal after the mould is filled.

This process is, as can be seen, uncertain and relatively dangerous. On the other hand, by means of the method and device A of the invention, it is possible to form and fill the axial hollow of the ingot in a perfect manner and avoid formation of hollows distributed within the ingot. In plan the shape of the device of the invention is preferably substantially homothetic to the cross-sectional shape of the ingot mould L It is in every respect similar to that of the foregoing embodiments but it could be more convenient to replace the water 16 by cotton waste or tow soaked in water, or wet Wood saw-dust or charcoal Whose water absorbent powers are considerable, this material being placed in the device before the latter is placed on the surface of the molten metal bath, which is done at the latest when the level is at tu. At this moment the central aperture 4 is provided with an athermanous and exothermic powder 17 conforming to one of the numerous known compositions, which may be enclosed in a paper or plastic envelope. Thus the jet of metal 18 can pass through the level tu (instead of being stopped by the already solidified upper layer obtained in the conventional method using an uncontrolled spraying) and rise to the desired height, whereas the water-soaked fibrous mass 16 accelerates the solidification of the zone ptus surrounding the jet 18, which zone would have remained liquid or pasty for a longer period of time if a sudden spraying had been employed, this spraying necessitating a certain delay to insure that direct contact of the spray water does not result in accidents, which delay is very limited by the solidification of the basin and the bottom casting molten metal channels, this being facilitated by the fact that it is possible to place the device A in position by means of the handling rings 5 well before stopping the pouring jet or gate.

Another considerable advantage is that the excess metal remaining liquid at 19 could be made to completely fill the axial shrinkage hollow by calculating its volume.

FIGS. 6 and 7 show utilization of another device A of the invention in the case of an unkilled ingot x Whose head has started to solidify at the periphery in the ingot mould L and forms a curved portion 28 on the surface.

In this case, the solidified peripheral part is allowed to become much thicker and reach the line a d (REG. 7). Thereafter there is placed on the solidified part a frame 29 which is apertured or not and around which is fixed at its base a layer or a fabric 39 soaked with an aqueous solution according to the invention as described hereinbefore. This fibrous mass has an area slightly greater than that of the cross-section of the mould at the head of the ingot in the course of solidification so that by forcing it into position it forms a cup-like vessel. It will be observed that the opening formed by the frame 29 is slightly shorter and wider in plan (at a d than the inner limit of the solidification of the peripheral part shown by the contour a d The ingot is closed in exactlythe same manner as described hereinbefore in respect of unkilled steel.

It should be noted that, according to the invention, an aqueous solution or even merely water could be poured at 31 into the cup formed by the layer 3% if this is found necessary. Another feature is that the device A could be covered with a fabric 32 soaked in accordance with the invention if the steel has a tendency to overflow from the frame 29, which would not incidentally present any grave inconvenience since it would solidify upon contact with the soaked fabric 30.

A similar layer or fabric could of course be used in the other foregoing examples, if necessary.

According to an improvement of the method of the invention described hereinbefore, the cooling effect in the direction from the periphery toward the center of the upper surface of the ingot could be graduated by varying the supply of liquid in contact with the poured metal by varying at least one of the following factors: the duration, the amount and moment of the supply of liquid, and the permeability of the support' Thus the thickness at each point of the peripheral layer of the superficially solidified metal could be controlled as desired at each instant so that this thickness decreases according to any desired law in the direction from the pe riphery toward the non-solidified central zone.

Further, the support--which could be as desired annular, similar to the supports described hereinbefore or otherwise-could be formed by a series or nest of parallel passageways formed by an assembly of walls which are at least partially incombustible, these passageways being perpendicular to the two large parallel faces of a flat-shaped volume in which the nest is inscribed.

Thus, in the embodiment shown in FIGS. 8-16, the device of the invention adapted to control the cooling of the head of an ingot x of effervescent steel poured in an ingot mould L comprises the combination of a support A for water or other liquid and a set of pipes B which effect a controlled supply of this liquid to the support A The support constitutes a nest of parallel passageways 31 defined by the walls 32 of strong papencardboard or other material, which is either incombustible by nature or substantially fire-proofed.

The support or nest of passageways is inscribed in a fiat-shaped volume having two large parallel faces having sections CC and DD (FIG. 8). Its shape in plan is such that it corresponds-apart from a very small clearance of between about several millimetres and a centimetreto that of the inner contour of the entrance 33 of the ingot mould L Its outer surface 34- is therefore cylindro-prismatic. The passageways 31 are perpendicular to the large faces of the support. The length of these passageways is from about 5 to 1-0 centimetres. Their cross-sectional area is preferably less than 1 sq. cm.

The large upper and lower faces of the nest have concentric variations in level or steps whose longitudinal section (FIG. 8) and transverse section (FIG. 10) are respectively symmetrical relative to two perpendicular planes of symmetry X-X and YY, which correspond, when the support A is disposed in the mould, to those of the mould itself. These sections are such that this nest forms on its upper face an annular open cavity 35 constituting a trough for receiving the liquid. This trough has a vertical trapezoidal cross-sectional shape the corners .of whichare substantially rounded; this cross-section is. preferablyconstant throughout its 7 length. The nest forms on its lower face an outer upwardly divergent chamfer 36 and a central upwardly convergent cavity 37.

The passageways 31*, which have a constant crosssection, are substantially closed in the portion of the nest situated in the region of the annular cavity 35, the passageways being preferably closed at their base. The closure of the psasageways increases progressively in the direction from the lower edge 33 of the chamfer 36 to a line 39 which is situated in the central cavity 37 and V which, when projected on a horizontal plane, lies outside-or at least onthe projection of the upper inner edge 40 of the upper cavity 35.

The support A may be advantageously constructed from a band of a single wall corrugated board coiled on itself. This band consists of a plane sheet 4-1 (FIG. 12) to which are attached by an adhesive the crests of the corrugations of a corrugated sheet 42.

The band may be coiled on itself round a mandrel 43 whose very thin cross-sectional shape is homothetic to that of the ingot mould so that the block obtained by Winding the band (FIG. 11) has a shape, in plan, perpendicular to the passageways 41, corresponding to the cross sectional shape of the mould and such dimensions that it is capable of entering the mould with the aforementioned small clearance. The two large faces 44 and 45 are therefore flat and the block obtained exactly corresponds to the volume in which the finished nest is inscribed.

The single wall corrugated board could also be wound in the form of a ring and then deformed in the direction perpendicular to the passageways so as to provide a block having the desired shape in plan.

To obtain from the block formed by one of the methods described hereinbefore the support A shown in FIGS. 8-10 and FIG. 14, the following successive operations are carried out on the block, which is shown partially broken away in FIG. 11.

(a) The coils are slipped or offset relative to one another so as to impart to the block the intermediate shape shown in FIG. 13; this shape is such that the upper flat face 44 shown in FIG. 11 is hollowed so as to provide the trough 35, the lower face being formed into the chamfer 36, a portion 46 parallel with the bottom of the trough 35 and the cavity 37 which extends to the joint line 48 of the face 46.

(b) Pins 49 of steel or other strong material are then inserted in the block thus deformed so as to maintain the coils in the relative positions they now occupy.

(c) The block is dipped in a fire-proofing bath preferably composed of a solution of sodium silicate; the solutions giving the best results are those in which the ratio SiO /Na O is between 3 and 4 and the Baurn degree is between 38 and 40; the extent of fire-proofing obtained is obviously a function of the duration of dipping.

(d) The passageways are partially closed by subjecting the fire-proofed block, whose silicate has set, to a compression in the direction of the length of the passage ways so that the lower face 46 is pushed up to 50 so as to extend between the closed lines 38 and 39 (FIGS. 8, l and 14); to etfect this compression, which slightly extends into the surface of the cavity 37, the nest of passageways is compressed between a former, whose surface exactly corresponds to the shape of the upper face of the block as shown in FIG. 13, and a punch whose effective surface corresponds to the final surface 50. This compression results in deformation 51 of the walls of the nest of passageways; these walls are crum pled substantially in the form of an accordion and increase in thickness as their height decreases so that there is obtained a closure of the passageways which increases in the direction from the line 38 to the line 48 of intersection of the surfaces 54) and 37 on which the closure could be complete or partial as desired.

The spraying device B comprises a support and a set of supply pipes supplying water or an aqueous solution of treating product. The support comprises (FIGS. 8-10) two tubes or rods 52 which are parallel and fixed in adjustable position by means of collars 53 and locking screws 54 on two pairs of legs 55 adapted to bear against the upper transverse edge 56 of the mould L Fixed under the tubes 52 is a first pipe 57 which is in the form of a ring and has such dimensions that it can be located above the annular trough 35. Fixed to these tubes is a longitudinal pipe 58 adapted to be positioned in alignment with the unclosed middle portion 59 of the support A Each pipe 57 and 58 is provided with two pipe connections '60, 61 or '62, 63 which permits rapid and easy connection to two flexible supply pipes 64 and 65 (FIG. 9) connected by way of valves 66, 67 and a common valve 68 to a supply pipe 69 supplying water or an aqueous solution.

Thus the pipes 57 and 58 can be connected either in the direction of the major axis of the cross-section of the mould by the pipe connections 61, 63 as shown in FIG. 9, or in the direction of the minor axis of this crosssection by the pipe connections 60, 62 depending on the space in the foundry pit.

The pipes 57 and 58 are provided along their lower generatrices with outlet apertures 70 through which the water or other liquid issues (see FIGS. 15 and 16).

The device operates in the following manner:

The support A is placed on the molten metal bath x of steel or other metal as soon as possible after pouring the metal, for example within a period of one to six minutes if the ingot is being top cast. In the case of bottom casting, the support could be placed in position before.

In FIGS. 8, 10 and 14 it has been supposed that the bath x has started to solidify at 71 in forming a small upper peripheral rim 72; however, the solidification could occur with a substantially rounded fillet.

As the support A is fireproofed notably owing to its impregnation with sodium silicate, it resists perfectly well the heat given off by the metal. Since the silicate softens upon application of heat, the support A becomes slightly flexible, which enables it to apply itself well on the bath of metal x*. If this metal is effervescent steel, the support A clamps the effervescence which causes the steel to solidify sooner, since it is in a state of surfusion.

But above all, the support A which is sprayed with water or an aqueous solution, has for its purpose to activate the peripheral solidification, in other words to cause the solidification to progress from the periphery toward the center owing to the cooling effect produced by the evaporation of this water.

Water is first supplied through the valve 67 and through one of the pipe connections 61 or 60 to the lower pipe 57 which sprays this water into the trough 35 through its apertures 70. From this trough the water impregnates the cardboard and above all flows downwardly through the vertical passageways 31. It is evaporated by the heat given off by the molten metal bath x and thus produces a cooling effect which accelerates the superficial peripheral solidification of the ingot, whereas the center of this upper surface of the ingot is shielded from the cooling eifect by the cushion or layer of hot gases which fill the central cavity 37 and escape by way of the passageways of the corresponding middle portion 59 of the support A Owing to the progressively increased closing of the passageways 31 between the lines 38 and 48, it will-be understood that the cooling efiect decreases from the periphery toward the center of the support A. Thus by suitably selecting the closure of the passageways between these lines it is fully possible to control the solidification law. The ingot solidifies at the head end in accordance with successive contours, such as those indicated by the lines '73 and 74 (FIG. 14) which progress toward the center, the thickness of the solidified part decreasing in 9 the same direction in accordance with the law which is substantially inversely proportional to that of the closure of the passageways.

As soon as solidification is obtained along the line 74, the opening 75 of the ingot is limited to the part located under the uncompressed portion 59 of the support A Thus it is easy by spraying this part by means of the pipe 58 at the opportune moment to solidify the steel which attempts to rise in the passageways of the portion 59, but it is certain that as the solidification occurred along the lines 73, 74, this solidification has sufficiently reinforced the already solidified periphery of the upper part of the ingot to avoid projections from said periphery.

By orientating the solidification toward the center of the surface of the ingot, risks of explosion are avoided, since the portion 59 of the support A which remains fully permeable to the gases-in a way performs the function of a safety valve until the stopping of the ingot, that is, cessation of formation of gases in the ingot.

It will be observed, furthermore, that the gases emanating from the already solidified peripheral part through the dendrites of the peripheral transcrystallization are constrained to follow this solidified part, which retards their ascent at the periphery and concentrates them near the axis of the ingot. In this way there is prevented formation of a bridge of solidified metal, that is, obstruction of the central opening, which is extremely important since this makes it possible to rapidly stop up the ingot so as to avoid segregations of the elements which experience has shown to be intensified by the prolonged ascent of the gases.

Briefly, whatever the errors or production differences, the device automatically insures certain success by the evaporation of water in the vertical passageways which perfectly perform the functions of an evaporation regulator of the supply of spraying water.

The upwardly convergent lower face 50 is advantageous from the siderurgical point of view, notably when the steel has a strong tendency to rise.

In the embodiment shown in FIGS. l722 the device is adapted to permit application of the invention simultaneously to the metal poured in two ingot moulds L disposed in a pit 91 defined by a bank 92 from which the workmen operate.

The molten metal x has already been poured into the two moulds L and has started to solidify partially at its periphery 72 when the support A is placed on the surface of the liquid metal. Each of the supports A comprises, as shown in FIG. 19, a single wall corrugated paper band which is coiled in the form of a spiral (FIG. this band comprising a plane band to which are attached by an adhesive the alternate crests of the corrugations of a corrugated band 94 so as to form passageways 95 which are disposed transversely of the band.

Before coiling the band in the form of a spiral the corrugations of the corrugated band 94 are crushed in a decreasing manner in the direction away from one end B of the band so that the free crests of the corrugations are located in a plane EF which is inclined relative to the band 93, the included angle y being about a few degrees and the corresponding passageways '95 being crushed transversely to a decreasing extent from E to F, the passageways 95 having their normal constant cross-section in the rest of the band after F.

The corrugated band thus deformed is coiled, in starting from the end B, into a roll E (FIG. 20-) up to the other end of the band. In the circular disc thus formed the passageways 95 of the central portion have a crosssection which progressively increases from the axis Y-Y of the disc to the cylinder defined by the lines 96 and 96 which are at the same distance from this axis. The portion of the disc located within this cylinder corresponds to the portion EF of the band (FIG. 20).

Between this cylinder shown by the lines 96 and 95 in FIG. 19 and the periphery at 97, 97 the passageways 1% have a constant cross-section and in consequence the support has in the peripheral portion between the lines 96, 97 and 96 97 a constant permeability, or rather, a constant capacity for storing the treating liquid, whereas its permeability decreases progressively from the coil situated on the lines 96, 96 to the axis Y-Y, the corresponding passageways 95 being progressively crushed.

The support thus obtained is thereafter deformed in a mould which imparts thereto substantially the contour in plan of the ingot mould, for example that shown in FIG. 18 having rounded corners. The support is then given a cup-like shape by progressively slipping at the periphery the adjoining coils so that the support assumes the shape shown in FIG. 19.

It will be observed that a permeability increasing in the direction from the center to the periphery of the central portion 96, 96 of the support could also be obtained by tightly coiling the band on itself, the tightness decreasing in the direction from the axis YY to the lines 96, 96 whereafter the tightness is maintained constant.

Thus, it results from either of these embodimentswhich could be combined moreover-that when a liquid is poured into the cup-like support this liquid descends through the nest of passageways much quicker near the periphery of the support due to the uncrushed passageways 95 than in the central part where its descent could be practically nil or in any case very slight owing to the crushed condition of the passageways 95 Advantageously, the passageways 95, 95- could be closed on the bottom face of the support by a sheet of thick substantially fire-proofed paper 98, which is secured, by means of a sodium silicate adhesive or any other coating or suitable glue, to the lower edges of the coils. This sheet would only carbonize very slowly, if it carbonized at all, upon contact with the molten metal, the cooling efiect of the evaporation of the liquid in the nest of passageways preventing, or in the extreme case slowing down, this carbonization.

The supply of water or other liquid to the devices A pertaining to the ingot moulds L is obtained by means of an auxiliary supply. device B which comprises a carriage 99 (FIGS. 17 and 18) carried by four ca-stors 100 swingable about a spindle 1111 engaged in a sleeve 102 carried by the carriage. The latter is adapted to roll along the bank 92 for the purpose of supplying liquid to the supports A of the two moulds L irrespective of the positions of the latter in the pit 91, and thereafter to similar supports of other moulds adjacent these two moulds in the pit 91.

The carriage 99 carries a vertical tubular column "103, rotatably mounted at its base on a journal 1G4 carried at the center of the carriage 99. A screw 105 permits securing the column in position when desired. A collar 106 is slidable along the column (FIGS. 17 and 22) and is secured at the desired height by a screw 107. This collar is provided laterally with a sleeve 10% in which is mounted a boss 109 carrying a handle 110, a screw 111 securing the boss 199 in the sleeve 98.

By means of this handle -which is therefore adjustable in height and in orientation relative to the column 1tl3it is easy for the workman on the bank 92 to move the carriage 99 and orientate it and the column 103 in accordance with the work to be carried out, that is, in practically any direction.

Adjustably fixed in position by screws 112 on the column 103 are two brackets each comprising two collars 113, which are Slidable along the column and are rigidly interconnected by a tube 114 and a strut 115. Slidable in the tube 114, which is horizontal when the column is vertical, is a rod 116 which forms with the tube 114 a-telescopic arm. The rod 116 extends right through the tube 114 and terminates at one end in a control knob 117 or the like and at the other end in a sleeve 118. Slidable in the latter is a vertical tube 12-11 which is held inposition by a screw 119. This tube carries on its lower end a spray head 121 which will be described hereinafter. The water, or other liquid, is supplied to the two spray heads 121 or to all the spray heads carried by the device, for the latter could comprise if desired more than two bracketsin the following manner. A flexible pipe 122 (FIG. 18) supplying the Water or other liquid is connected by a pipe connection 123 to a pipe 124 fixed to the lower end of the tubular column 1&3. The water rises up the column which is connected to a head 125 at its upper end-and passes through cocks 126 (FIG. 17) to flexible pipes 127 the ends of which are connected by pipe connections 128 to the tubes 120 carrying the spray heads 121.

One of these spray heads is shown on an enlarged scale in FIG. 21. Fixed on the tube 129 by a weld or other means is a conical member 129 having a flange 139 on its lower periphery. A perforated flat bottom 133 is fixed to the flange 139 by bolts 131 and nuts 132. The central part of the bottom 133 can be closed by a flap 134 hingedly mounted at 135 on this bottom and maintained in its raised or closing position by a locking device 136 which has a control knob 137 and is biased toward its operative position by a spring 138.

When the flap 134 is in its raised position, the water or other liquid which enters by way of the tube 12a can issue from the spray head only through the periphery of the bottom 133 as shown by the arrows and falls on the corresponding support A in the peripheral region of the latter, that is, in the region which constitutes the annular vessel for this water and has uncrushed passageways 95 (FIG. 17).

The cooling effect of the evaporation of the water, which effect diminishes from the periphery toward the center of the support A results in the desired centripetal progression of the solidification of the head of the ingot.

If necessary, at the end of the solidification, the central part of the head of the ingot may be sprayed by withdrawing the locking device 136 and allowing the flap 134 to drop to its vertical position 134* under its own Weight and to the pressure of the water on the bottom 133.

The spraying device just described has many advantages:

The spray heads 121 do not rest on the ingot moulds, which permits a much stronger support for these heads, since their support on the ingot mould could be unstable, above all in the case of small moulds.

The spray head affords an excellent distribution of the water, particularly in the corners of the supports A The bottom 133 of the heads is detachable and can be easily replaced by any other bottom having it necessary a different arrangement of the perforations.

A slight swinging of these spray heads, controlled from the bank 92 by the rod 116 and the knob 117 acting on the tubes 120, permits shifting the jets of water issuing from the perforated bottom'133 and thus supplying all the passageways 95 of the support A even if the number of perforations in the bottom 133 is much less than the number of passageways 95.

FIGS. 23 and 24 show a modification of the spray head in which the conical wall 121 is secured to a curved bottom 139 thereby imparting to the jets of water issuing from the perforations divergent directions. Thus, by adjusting the height of the head relative to the support being supplied with water, it is possible to spray supports of difierent sizes with these jets.

In this modification, the selective spraying of the periphery and of the center of the support constituting a vessel, instead of being insured by means of the flap 134 of the preceding embodiment, is insured by a separate water supply to the central portion of the bottom 139.

iliary supply tube 140 which communicates through a flexible pipe 141 with a small auxiliary conical member 142 located inside the member 121 and connected to the central portion of the bottom .139. Thus by means of suitable cocks, it is possible to supply water to the periphery of the bottom 139 or to its central portion, as

desired. a 7

Although specific embodiments of the invention have been described, many modifications and changes may be made therein without departing from the scope of the invention as defined in the appended claims.

The spraying device shown in FIGS. 17, 18, 21 or 23, 24 could be used with the water-receiving supports of the preceding examples and conversely, the support having a variable permeability due to transverse crushing of the passageways shown in FIG. 19 and obtained from the band shown in FIG. 20, could be used with the spraying device shown in FIGS. 8 to 10, and even without the auxiliary spraying device, the water being poured directly into this cup shaped support.

The spray heads 121 shown in FIGS. 17 and 18 could be replaced on the column 103 by the perforated pipes 57-58 shown in FIGS. 8 to 10.

In the embodiment shown in FIGS. 17 to 21, the cupsh-aped support A instead of being obtained by coiling into a spiral the previously deformed band shown in FIG. 20, could be obtained either by successively winding a plurality of shorter bands one round the other, these bands having passageways whose cross-sectional sizes increase trom one band to the other, or by disposing in adjoining relation sections of corrugated bands which comprise in the central portion of the support either smaller passageways due to a smaller corrugation pitch of the corresponding corrugated band or to passageways crushed to a varying extent, the crushing decreasing in the direction from the centre toward the periphery of the support.

It is also possible to combine the transverse crushing of the passageways with a longitudinal crushing of their walls, as described with respect to the embodiment shown in FIGS. 8 to 14.

In a general way means other than a nest of passageways crushed to a varying extent, could be used for obtaining a permeability or porosity which decreases from the periphery toward the center of the support.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

1. Method of treating an ingot in the course of solidification of the poured metal in an ingot mould comprising cooling in a controlled manner the peripheral portion of the top surface of the ingot by supporting on said peripheral portion a vessel and supplying to said vessel 3. material comprising at least in part a liquid capable of evaporating in said vessel whereby the evaporation of said liquid under the efiect of the heat of the ingot produces a cooling effect for cooling said peripheral portion.

2. Method as claimed in claim 1, wherein water in the free state is used as said material.

3. Method as claimed in claim 1, wherein said material is a material containing water of constitution.

4. Method as claimed in claim 1, wherein said material is a material containing water of crystallization.

5. Method as claimed in claim 1, wherein the support is permeable to said liquid so that said liquid penetrates the support.

6. Method as claimed in claim 1 comprising thereafter supplying water at the center of the surface of the ingot at the end of solidification.

7. Apparatus for use in an ingot mold comprising a plurality of cardboard walls constituting a vessel having relatively large upper and lower surfaces and defining between said surfaces a multitude of vertical and parallel capillary passages, said walls defining in said upper surfaces an open annular channel of substantially U-shaped cross-section adapted for accommodating a vaporizable medium whereby said medium is adapted to descend through said passages due to capillary action.

(References on following page) 13 References Cited in the file of this patent 2,679,080 UNITED STATES PATENTS 2794224 2,853,754 1,895,135 Rohn Ian. 24, 1933 2,023,957 Hewgill Dec. 10, 1935 5 2,219,864 Dostal Oct. 29, 1940 2,024 2,402,833 Mumma et a]. June 25, 1946 276,288 2,414,269 Nieholls Jan. 14, 1947 494,493

14 Olsen May 25, 1954 Sylvester June 4, 1957 Paddock Sept. 30, 1958 FOREIGN PATENTS Great Britain Sept. 7, 1855 Germany July 9, 1914 Belgium July 1, 1950 

